Hydraulic press with pressure-intensifier.



B. 'GERDAU. HYDRAULIC PRESS WITH PRESSURE INTENSIHER.

' APPLICATION FILED HOV. 25, 1903.

1,007,349, Patenfed 00t.'31,1911.

BERTHOLD GERDA U, OF .DUSSELDORF, GERMANY.

HYDRAULIC PRESS WITH PRESSURE-INTENSIFIERT Specification of Letters Patent.

Application filed November 25, 1903. Serial No. 182,635.

To all whom it may concern:

Be it known that I, BERTHOLD GERDAU,

.chief engineer, and a subject of the King of Prussia, residing at 13 Neanderstrasse, in the city of Dusseldorf, Kingdom of Prussia, and German Empire, have invented certain new and useful Improvements in Hydraulic. Presses with Pressure-lntensitiers, of which the following is a specification.

This invention has reference to hydraulic presses, in the operation of which pressure internifying devices are made use of, the relation between the press piston and the piston of the intensifying device being such that the withdrawal of the pressure intensifier piston is efi'ected directly on account of the press piston exerting a pressure upon the liquid inthe press cylinder also during the withdrawal of the lntensifier piston.- Such presses of comparatively small size are usually expected to work very quickly and the short stroke required with such presses is secured by acting upon the piston in the intensifier cylinder by means of valves.

My invention is intended to provide means whereby the length of stroke may be adjusted in a simple and expeditious manner and the invention also aims at a very compact arrangement of the'several operating members.

In the accompanying drawing, a press embodying my invention is illustrated in part vertical section.

In the drawings: a is the cylinder of the press, the said cylinder being secured to the frame of the machine. In the cylinder the hollow press piston Z) which carries the cross head of the press, is guided. The piston rod 6 of the pressure intensifying cylinder (1 which is arranged above the press cylinder, passes through the upper cover of the press cylinder and into the cavity of the piston. The said pressure intensifying cylinder is provided with passages for the admission and the discharge of steam.

In view of the invention referring chiefly to presses of small size, the press cylinder is provided with a withdrawal device which comprises only one withdrawal cylinder. The said withdrawal cylinder 6 is placed very near to the press cylinder and at the interior of the said WithdrawaLcyli-nder the piston rod is arranged eccentrically upon the withdrawal piston, as shown, in order to reduce the distance between the pistons f and b. In consequence of this eccentric arrangement, the bending strain is reduced as compared with an arrangement where the rod would act from the center of the withdrawal piston, and the thus reduced bending strain is distributed over several points, that is to say, upon the guides of the main press plunger and upon the withdrawal piston. By the said arrangement of parts the most compact construction imaginable of the machine is produced while at the same time the bending strain. is reduced.

Upon the other side of the press cylinder I provide a second pressure intensifier. The said second pressure intensifier consists of the steam cylinder it, the intensifier piston rod 71 of which is movable in a second intensifier cylinder la. This cylinder is of such capacity that itcan receive the entire amount of the pressure liquid which is displaced by the press piston b and the piston rod 0. The lower end of the said cylinder 70 is connected to the upper end of the press cylinder at by a special controlling valve casing and in the top of the said casing is mounted the special check valve Z which in the normal position prevents the high pressure from the press cylinder to get at the controlling mechanism m which regulates the feeding'of the press cylinder from the second pressure intensifier. The said controlling mechanism at and the cmitrolling valve n for the steam cylinder of the second intensifier are governed by a single controlling lever 0 so that they are dependent upon each other. By a suitable arrangement of levers, the check valve 7 is also made dependent upon the movement of the controlling lever. the extension of the guide Patented Oct. 31, 1911.

rod 7) of the valve being capable of actnation by means of the actuating lover of the controlling mechanism 7/1. There is no special need of the comiection ot' the lover o with the several controlling valves being effected by mechanical means, such as rods. ropes or the like and the operation may also be effected by power transmitted by hydraulic or electrical means.- Besides the controlling mechanism m is not absolutely necessary. It only serves as a safety supplemental member by serving as a second means for closing the connecting conduit between the press cylinder and the second pressure intensifier, but under certain conditions it may also be discarded.

The operation of the improved device is as follows: The intensifier piston and the press piston, as Well as the withdrawal piston are normally in their highest position when at rest. The steam valve 7 of the main intensifier is open to exhaust. If it is now desired to advance the press plunger b in a downward direction so as to be slowly operated, the steam valve n of the second pressure intensifier is opened for the admission of live steam by turning down the controlling lever 0, by which means the controlling.

valve m is also operated at the same time and opens up the connection between the said second intensifier and the press cylinder. The steam which enters the steam cylinder of the second pressure intensifier, depresses the piston rod 71 into its corresponding intensifier cylinder is and forcesthe water contained in the latter, through the open valve m and through the automatically opening check valve Z mto the press cylinder 72. The pressure liquid which leaves the intensifier cylinder is has sufficient pressure so as to allow of the pressure on the press piston b to overcome the counter pressure of the withdrawal piston at any rate, whereby the press piston is forced downward as soon as the pressure has also forced the intensifier piston c upward into its highest position, in case the piston did not already assume this position. This action is illustrated in the drawing. The downward movement of'the press piston may be checked at any moment by taking off the pressure from the press cylinder which is effected by a corresponding movement of the controlling lever 0. The valve Z is closed by the pressure from the press cylinder, the valves m and 'n are closed by the controlling lever 0. After this the actual operation of the press is commenced, by actuating the first intensifier piston 0. By the action of the controlling mechanism .5- alone which is of well known construction, the steam admission valve is opened in the valve casing 1 while the discharge valve is closed, so that the intensifier piston is advanced together with the press piston. At the completion of the stroke, the controlling lever is reversed and the admission valve at the cylinder d is closed thereby; the discharge valve is opened and then the return movement of the press piston is effected by the action of the pressure operated withdrawal piston, by which means in consequence, the intensifier piston 0 is also immediately returned into its initial position and the order of operations is then repeated. The press piston in this operation is always returned to theinitial position which is determined by the pressure in the press cylinder. The cushioning action of the steam is always at the rear of the intensifier iston. When the transmitter piston is a vanced however, a quantity of air is compressed in front of the same,'as the piston is provided with a projection fitting closely in the opening in the bottom of the cylinder-d, so that upon the descent of the piston only a very narrow annular slot remains, which opposes a considerable resistance to the passage of the air. In this manner an air cushion is formed which opposes a resistance to the movement of the piston in the event ofslipping of the object to be pressed and the consequent sudden decrease of resistance. If it is desired to withdraw the press piston b in an upward direction so that it assumes another starting position, the steam valve n should be set for exhaust and the controlling valve m has to be opened again and at the same time the check valve l is raised and opened by mechanical means as shown. The great pressure which acts upon the withdrawal piston, which however may be still increased by steam pressure, is suificient, to return the press piston and thereby to raise the intensifier piston 0 to its highest position, but the said pressure is also suiiicient to force the second intensifier piston back by displacing the water in the press cylinder 1) and forcing the same into the intensifier cylinder is of the second pressure intensifying device, the said intensifier piston being moved back, as far as this is required b the position of the press ram 6 just required. This is the final position shown. In the inoperative position ofthe lever o, the check valve Z is closed and the controlling valve mechanisms m and n are in their middle positions. The raising of the steam piston of the second pressure intensifier maybe further facilitated by ad-.

mitting steam below the same, the steam being reduced to a lower pressure, it required, by a reduction valve.

\Vhat I claim and desire to secure by Letters Patent of the United States is 1. In a press of the character described, the combination with a press cylinder, a piston working within said cylinder and a pressure intensifier cooperating with the piston, of a second independent intensifying apparatus, including a cylinder, of a capacity equal to the whole of the quantity of the liquid required by the press cylinder when the largest stroke is performed, the

second cylinder being directly connected inder, the latter cylinder being of sufiicient piston working in said cylinder, and a pressure intensifier operating directly on said piston, of a second, independent, intensifying apparatus, comprising a power cylinder, and a pressure cylinder located adjacent the press cylinder, a piston having a head arranged in the power cylinder and its stem extending into the pressure cylinder, a single conduit connecting the last said cylinder of the second intensifier directly with the press cylinder, a device for controlling the passage of liquid through said conduit, and means for simultaneously actuating said controlling device and the inlet valve of the pressure cylinder of the second intensifier.

4. In a press of the character described, the combination with a press cylinder, a piston working within said cylinder, and a pressure intensifier cooperating with the piston, of a second, independent, intensifying apparatus including a cylinder connected directly with the press cylinder, a rotary valve in the connection between said cylinders, an independent check' valve in said connection, and means for simultaneously actuating both said valves.

5. In a press of the character described,

the combination with the press cylinder, its

piston and pressure intensifier connected therewith, of a withdrawal cylinder, a piston therefor, and an eccentrically arranged piston rod connected. with the withdrawal piston and press piston.-

6. In a press of the character described, the combination with a press cylinder, a piston therefor and a pressure intensifier connected therewith, a withdrawal cylinder located adjacent to the press cylinder, a piston in said withdrawal cylinder, and a piston rod eccentrically mounted in the piston at a point between the centers of the press and the withdrawal cylinders, said piston rod being connected with the pressure piston.

7. In a press of the character described, the combination with a press cylinder, a piston therefor, of a withdrawal cylinder and a piston for said withdrawal cylinder, and an eccentrically arranged piston rod connected with the withdrawal piston and the pressure piston.

8. In a press of the character described, the combination of a press cylinder, a plunger piston working therein, means for operating said piston and an independent in tensifying apparatus comprising a cylinder directly connected with the pressure cylinder, and a piston working in said second cylinder, said second cylinder being constructed so as to be of suflicient capacity to receive the greatest quantity of liquid displaced in the press cylinder at full stroke.

9. In a press of the character described, the combination of a press cylinder, a driving piston working therein and having a cavity therein, a plunger piston Working in said cylinder and said driving piston, means for operating said plunger piston, and an independent intensifying apparatus 'comprising a cylinder directly connected with the press cylinder, a piston working in said second cylinder, said second cylinder being constructed so asto be of suflicient capaeity to receive the greatest quantity of liquid displaced in the press cylinder at full stroke.

10. In a press of the character described,

the combination of a press cylinder, a driving piston and a plunger piston working therein, means for operating the plunger piston, and a second cylinder connected to said first cylinder by a direct connection, a

piston working in said second cylinder, said second cylinder being constructed and arranged to receive the greatest quantity of liquid displaced in said press cylinder at full stroke.

11. In a press of the character described, the combination of a press cylinder, a driving piston and a plunger piston Working therein, a second cylinder located adjacent the press cylinder and having a piston therein, a direct connection between the cylinders, andv a controlling member in said direct connection.

12. In a press of the character described, the combination of a press cylinder, a driving piston and a plunger piston working therein, a second cylinder located adjacent the press cylinder and having a piston therein, a direct connection between the cylinders, a controlling member in said direct connection, fluid pressure operating means for operating the piston in the second cylinder, and a single means controlling the operation of said fluid pressure operating means, and controlling member.

In witness whereof, I have hereunto signed my name in the presence of two subscribing witnesses.

BERTHOLD GERDAU.

Witnesses PETER LIEBER, IVILLIAu Essnxwnm. 

